Spikes vs "soft feet" under speakers... - Page 2

I know just the tool for that job!

Will these stands be butted to a wall or few feet away?

Given that the standard speaker placement says at least 1 foot, it will probably be no more than that. So I am thinking that the base of the stand will 6-8 inches away from the wall, toed in towards my main LP, which I think will put my L&R mains 12 inches from the wall.

Do what I did.

Get the speakers. Place them in position.
Get the wife and kids stand around them.
Make a speech and make it clear that anybody who manages to even touch, let alone knock down the speaker will be grounded for 6 months. No excuses.
Worked wonders for me.

Totally will do that. What stands do you have??

What about the kind of speaker stands that allow you to put sand or lead weight in the base? That would keep 'em pretty stable if kids don't bump 'em too hard.

hmmm. thats a good possible idea...

I can attest to this working. I didn't go as far as making my wife and kids stand around my speakers, but i did lay down the law as far as anyone touching anything. As soon as my wife and I got engaged and discussed having kids, I made it very clear that she would have to help in enforcing the no touch rule.

I have a soon to be 5 year old boy and a 2.5 year old girl, and I've instilled in them very early on that "we don't touch daddy's speakers." It doesn't even phase my son at this point. He knows that he should play with his toys on the kids side of the family room. My daughter actively reminds everyone not to touch. I was reading Home Theatre magazine the other day and she saw an ad for some speakers. She said "those are like daddy's speaker and we don't touch!!!!"

Ha...I put them on $$9.99 IKEA LACK Coffee table on the Left and right corners of the room.
the velodyne subwoofer goes underneath them with 4mm to spare.
Perfect.

Here are the infinity floorstanders using the Def Tech speaker brackets/legs....awesome stability.

Chikoo: I am looking for speaker feet like those shown in your picture. However, when I googled "def Tech", all I got was (1) Definitive Technology (no feet there), and (2) a Japanese rock band. Can you direct me to where I can find these?

Manly spikes.

The 'reason' for spikes is that some people experience the distortion that the vibrating floor adds as positive. I've read numerous different superlatives for this. And many physically ridiculous claims on how spikes 'function'. And if someone likes the coloration, then there's absolutely nothing wrong with that! After all, it's enjoyment we're after. But calling things for what they are and basing advice on sound(!) science is at least what I prefer. Heck, if we understand what makes what coloration, not only do we learn how to remove them if that's our choice... or create them, if that's our choice.

Soft feet chosen for the weight of the speaker works much better. Making sure that while there is possible movement according to Newton's third, it's a more horizontal and well dampened movement, rather that inducing a rocking, resonant behavior on spikes. It's counter-intuitive to a lot of people, thinking this miniscule movement - but they're not aware just how much a speaker on spikes is moving- rather imagining that to be the more solid one. An accelerometer experiment will cure that, though.

Spikes is unfortunately a selling point, so there are many speaker manufacturers who put connections for spikes on their speakers even though they know they will behave worse. Some has taken a cheating approach and connected the spike connectors soft to the cabinet to turn them into pseudo-softfeet. It's probably also quite lucrative extra money for dealers - selling spikes - so not a lot of them will tell you otherwise. Most probably innocently believe in them, though. When you hear something make a difference and it's one you like, it's so easy to also believe it's because it's also technically better...

Some brilliant engineers here.

There is improved imaging and low-level detail to be gained from spiked speakers (i.e. mechanically coupled), simply because they “hold still” during high playback levels and transmit energy from the enclosure itself. The actual weight of the speaker acting as a counter force to driver movement is also an important factor (i.e. more weight is superior, up to a point of diminishing return)

The action-reaction of a cabinet moving even slightly tends to degrade imaging accuracy and low-level resolution, but will create a sense of “warmth" (warmth being best described as a "warmer" sound due to slight cabinet movement, which is out of phase with the speaker drivers, thus actually distorting playback). It is the same effect as compression of the signal to the driver, because the full peak cannot be reached. Heavy, rigid cabinets on spikes will sound more accurate for any given driver complement.

One must be cautious however as to what sub surface the enclosure is being coupled to. When spiking to a wood floor, mechanical energy will transfer to an unstable resonating surface, thus creating a separate and, of course, out of phase enclosure of the floor itself. In this instance some decoupling is desired to reduce this effect. Make no mistake however, when you decouple a vibrating device from a mechanical "drain reservoir" (i.e. the floor) the vibrations will remain in the speaker enclosure, thus creating phase problems.

Blu tac under speakers will only serve to add an elastomeric foundation which will keep vibrations within the enclosure itself, thus also inducing the cabinet to become out of phase with driver movement.

The idea is to "de couple" the speaker from the floor to minimized vibrations going to or away from the speaker. The idea is that as the square area contacting the floor approaches zero (the tip of the spike), then there is less surface area to act upon. I have an engineering degree, and it sounds hocus pocus to me. In the reality, I would say it makes little difference. Same as expensive cables sounding or looking better. Spend a lot of money, you WANT to believe it makes a difference. I also see no double blind listening tests of speakers with/without carpet spikes.

So I handmade some maple platforms for my hybrid ESLs. They are 2" thick and are on hardwood floor. The reason I made them is because of how much vibration went into the floor which exaggerated the bass by a good amount. But even with the maple platforms setup how they currently are I still get the bass going into the floor.

Should I still be spiking the speakers to this maple platform or use the rubber feet covers under the speakers instead? Should the maple platform be spiked into the floor instead of being on rubber feet?

Some clarity would be awesome! Too many options.

You should weigh your speakers front and back and then order properly weightmatched soft feet for correct decoupling.

Do you have any recommended feet that you use? Does sorbothane do the trick?

I've heard that it can stain the wood though and would prefer something safe for both my speaker finish and platform finish.

I use Sonic Design. Never heard of any stains from those.

Should the subwoofer use soft feet as well? Is there anything that you still use spikes on in your home theater?

Yes. It's a bit harder to achieve the 1:1000 weight ratio moving weight (cone+air) to cabinet as the rule of thumb is, it seems to end up more around 1:200 for subs, so if you're building your own subwoofer cabinets - make them heavy! My theater subs are triangular and the three corners therefore weigh close to the same, just half a pounds difference, so they will have three identical feel. My normal box shaped once in the tv-room has different for front and back due to being front heavy.

My livingroom subs are unfortunately not on any feet at all. I didn't know any better when I built them and they are almost full ceiling height, so I don't think I can dismantle those to put feet below and get them back in place afterwards. At least they're quite heavy, each tower of four weighs at least 250-300 pounds - I built them in 1" MDF, so that's probably closer to 1:500 ratio. Perhaps one day I'll bite the bullet and try, though.

One good thing about it is that the function is linear, so if you suddenly decide to stack two subs, you can just use all the feet of the two below the lower one. (Never put the upper one with soft feet on top of the lower one, that changes the resonance frequency of the whole stack. )

No spikes anywhere. Had them once upon a time on both my Canton Digitals and the stereo rack, but they're all gone. I haven't completed my order of the feet for my theater yet, will be sending the money after my next pay check... it's 70 feet in total, so I got myself a small discount too. Putting surrounds on them is probably overkill, but I like overkill.

That may be the idea but it is destined to failure. Little pieces of rubber thankfully do little to attenuate the major source of sound leakage from speakers, which is via the speaker cones. Doooh!

People think that because the speakers sit on the floor that the major source of sound transmission is through the cabinet, completely ignoring the fact that the speaker fills the room with sound and the floor usually acts like a giant sounding board. Spikes, sorbothane, whatever you don't want to mess with the sound coming out of the speaker drivers and that is the 500 pound gorilla in the room.

If you want to cut sound transmission through a wall or floor, the best solution is some kind of mass-loaded resilient mat covering the whole surface.

This covers sound transmission through walls: http://www.soundproofingcompany.com/soundproofing101/understanding-stc/

The same basic principles cover floors and ceilings, but the approach changes the most for floors: http://pliteq.com/downloads/geniemat-rst/GenieMat_RST_Product_Brochure.pdf

That's definitely true about my theater problem. But on the other hand - spikes and certain floors and apartment building methods do not work very well. Given the floorings preferred here in Sweden and the way a lot of buildings have been constructed, there is a high enough success rate in minimizing the disturbing of neighbors that it may be an idea to try if one has that kind of problem. How well it translates to building methods outside Sweden, I have NO idea, therefore the tip may be useless.

If this video is any guide, http://www.youtube.com/watch?v=yZ0WlbT4flE both Swede and the US are big on "stick built" houses. Differences seem to be mostly related to whether the construction happens mostly on site or in a factory. In the US we do both, but manufactured housing is far more common at the low end of the market. A major trend in more expensive houses is the use of premanfactured trusses and built-up joists. But it is still all sticks and panels.

Concrete floors mostly show up in commercial buildings and large apartment buildings.

Very interesting. Thanks. My house was built 1999/2000, btw

( But it was the concrete apartment building I was referring to, though )

I may be wrong... (and very probably am wrong ) but it looks like there's an interesting graph on page 4 of that brochure.

It seems to say that all the different product dampening characteristics come together at the 80Hz minimum they have graphed... so would it be fair to assume that all the products are similarly effective/ineffective at the sort of frequencies that Subs put out?

So it seems. I was looking at other approaches and below 40 Hz it is fairly amazing what doesn't work! Thing is that > 60 Hz is boom and < 60 Hz is thud. Boom is more irritating to most. The sensitivity of the ear is falling off pretty fast and that helps.

At what SPL would the floor acting as a "springboard" from the sound be the issue and not vibration from the speakers into the floor? If the room isn't completely sealed can this still become an issue?

Any SPL since the proportioning should be linear.

Sealing the room should not make much difference if it is decent-sized. Of course sealing the room up minimizes airborne transmission which is usually very strong.

Wow - did I "under think" this aspect of my home theater, or are others "over thinking" this??

Truly I ask with genuine interest, and I've been know to go OCD on some items....

What I did, fwiw.
(my basement HT is on a slab floor, premium carpet and the best pad I could afford under the carpet, quite thick/plush.)

a) Floorstanding speakers.
My Paradigm Monitor 9's came with outboard feet with spike's, I use them to angle the speaker slightly above the first row so the people in the second row don't get the mid/high blocked.
The rear spikes are almost all the way twisted in, there is a lock nut, the front spikes are not quite all twisted out. Both them "punch" into the carpet.
I have blue painters tape on the carpet to align the speakers in same place when I move them for cleaning/etc, so no need to re-run audyssey.


b) Center channel
My center channel is below the HT screen, I made custom wood blocks to angle the speaker above the first row so the people in the second row don't get the mid/high blocked.
I also used soft sponge like material, its black and I think used to line cabinets for glasses/etc, you can see it between the wedge and the speaker, it is also between the wedge and the shelf base.
It keeps the speaker in place nicely. and I was hoping to isolate the speaker from the shelf somewhat with it....but not obsessed with that aspect either.
The center channel front is slightly ahead of the shelf edge, so no edge sound diffraction issues.


The shelf is attached to the wall, when I built the HT I put treated 2 x 4 's between the engineered concrete foundation studs, knowing a center speaker would be there. It is very solid.
You can see my drywall guy leaning on them here



c) My 11.1 wide speakers
I made these in-wall recess area to hold them, the bottom shelf is lined with same material used for my center channel, I had it leftover from the project.
Also, use bumpers in the front to tilt these slightly above the first row so the people in the second row don't get the mid/high blocked.
(the recess is lined with 2" OC703 also)



So, I've used both spikes and "soft material" for what I think is a practical usage of them, am I missing something here???
Edited by mtbdudex - 2/16/13 at 3:40am